Jaw control for chuck devices



Dec. 15, 1953 M. H. EMRlcK JAW CONTROL FOR CHUCK DEVICES Filed Nov. 30, 1951 Tini.

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Manni-Ima A xNvENTOR MELVIN H. EMRICK Patented Dec. 15, 1953 UNITED STATES PATENT OFFICE .IAWCONTBOL FOR CHUCK DEVICES MelvinH. Emrick, J 'amaicaN. Y.

Appliea-ton'NovemberBO, 1951, Serial'No. 259,139

8 Claims..

This invention relates to chuck devicesfor supporting drills, taps and the like. More particularly, the invention deals with the resilient support or" the tool gripping jaws of devices of 'this kind to provide a simple spring. action of the jaws, as well as to position the jaws. within the chuck, thusv dispensing with the use of the conventional guide grooves for guiding the iaws in the chuclrbody.

The novel features of the invention will be best understood from. the following description, when taken together with the ac.F.ornpanyingl drawing, in which certain embodiments or" the invention are disclosed and', nl which, the separate parts are designated by suitable reference characters in each of the views and, in which:

Fig. 1 is. a side View of a chuck showing the lower portion in transverse section.

Eig. 21 is a View similar to Fig. l', showing,r only a part of. the construction and with .the jaws in a diiierent position.

Fig.. 3 is a section on the line lli-3. or Fig. 2 taken through the jawsv and the jaw operating sleevey only; and.

Fig. 4 isa view,v similar to Eig. 2, omittingpart oi the construction and showing a modiiication.

in Fig. l of thel drawing., I have shown at il! the. body portion of a. chuck, which has a central cylindrical portionv il, an outwardly tapered upper eno. i2, a reduced neel: or collar portion 3 and. an externally tlneafieoL enlargement. i4.. The enlargement is has a conical bore IT: which flares outwardly in the direction of the lower end of the threaded enlargement M5.

The central cylindrical portion 'il has a transverse bore, partially represented by the recessed sides in which the shank' gripping members i? and l are disposed, as will appear through a transverse boreI is, which. opens into. the rst named bore at a. point offset with respect to the center thereof. rShe transverse bore .I9 gives vision for positioning of the shank between the.

members il and At il shown a left and' right-hand screw for actuating the members il' and IS.

lin threaded enffagement. with the renlarged threaded portion M is a bore operating sleeve not or. cap having` the usual gripper surface E2 to facilitate hand rotation thereof; The lower wal1 Z3 oi the nut 2i has a central bore '2li for reception or" the shankv of a. tool to be presse r into the chuck between a plurality of jaws 25, four jaws being employed in the construction shown, note Fig. 3.

As each. jaw 25 is of the same construction,

2 the. brief description ot one will apply to all and similar references Will be used on each jaw. Each jaw has ai vbevelleri` outer. surface 26 adapted to operate on the conical bore l5 in movement of the jaws inwardly from the fully open position shown in Fig. 1. of the drawing to the fully closed position, shown in Figs. 2 and. 3.

The jaws are generally triangular in form and their lower'edges 21 rest upon the wall 23; whereas, their inner edges 28 are contracted to form the tooll gripping surfaces or jaws, as will be apparent, and these jaws are slightly concavecl, as will appear from a considera-tion of Fig. 3 of the drawing.

The. gripping -surtaces are recessedV as seen at 2S preferably at a position slightly closer to the lower edge 21 than' .the upper ends of the jaws and, fitti-ng in the recesses 29, are' the crossheads Sii of yoke-shaped; spring members 3l. The side portions of the spring members 3,1, adjacent thecrcssheads 3o, 'are' bowed radially, as seen at 32, to .give spring properties to these members and also to spread over side surfaces of the jaws 25, as will be apparent. The ends of the spring mem-bers t in apertures 33 in the wall 23. .It will thus be. apparent' that the spring members are definitely positioned on. and are movable with the nut 2l in. rotation thereof for movement of the jaws from the position shown in Fig. 1 to the position shown in Figs. 2.y and` 3. In Fig. 3 of the drawing, the neck I3 and enlarged portion I4 are omittedA for sake of clarity in the showing. VIn other words, the section would be a section through. the nut 2i detached with respect to the body l0.

in Fig. 3, part of the gripper surface 22 has been indicated again to simplify the showing, it being,r understood that the gripper surface 22 ex tends the `fnl-l `circumference of the nut 2|.

With the structure shown in Figs. 1 to 3, it will be understood that the spring members si are tensioned tonormally support the jaws 25 in the extended position shown in Fig. i of the drawing inward movement of the jaws to the position shownin Fig. 2 increases the tension of said spring members.

In Fig. 4 of theclrawing, kI have shown modi lisation, wherein the chuck body isy the same as in the: structurey shown in Fig. 1, 'the neck portion i3* and enlarged threaded portion lli" only being shown. The enlarged threaded portion I4" has,. at its lower end, a recess 34 for receiving a jaw' supporting ring 351 The jaws 225 are identical with the jaws 25, as are also the springl members Si', the only difference being that the ends of the spring members operate in apertures 36 in the ring 35, so as to be supported by the ring and the nut 2| is also preferably recessed, as seen at 31, so as to minimize the surface engagement between the nut and the ring, as indicated at 33.

With the structure shown in Fig. 4, it will be understood that the jaws 25 will establish frictional engagement with the conical bore I and thus minimize rotary movement of the jaws in said bore; whereas, with the structures shown in Figs. 1 to 3, inclusive, the jaws will rotate with the nut 2l in movement of the jaws into open and closed positions.

One of the advantages in the jaw mounting and operation herein disclosed is in eliminating the use of the conventional guide grooves, as commonly employed in chuck bodies to guide the jaws in their radial movement, 'thus avoiding the stresses and strains and wear which prevails in devices of this kind. With the present construction, the wear is distributed throughout the entire surface l5, i5 and so proportioned as to give longer use to the chuck device.

In Fig. 4, the jaw member between and behind the two jaw members 25 has been omitted for sake of clarity.

It will be noted from a consideration of Fig. 1 of the drawing that a split ring 39 is mounted in a groove 40 of the nut 2| to retain the nut against accidental unthreading from the body I0. Removal of the ring 39 will facilitate detachment of the nut.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A chuck device of the character described, comprising a tubular chuck body having an eX- ternally threaded lower end portion, said lower end portion having a conical bore opening outwardly through said end, a plurality of tool gripping jaws mounted in said conical bore, said jaws having bevelled surfaces operating upon the walls of said conical bore in controlling movement of the jaws toward and from each other, inner edge portions of the jaws having elongated gripper surfaces, said gripper surfaces having recesses, means controlling positioning of the jaws one with respect to the other, a yoke-shaped spring engaging each of caid jaws, each spring having a crosshead and side members, the crossheads being arranged in said recesses, and said springs being tensioned to maintain the jaws in constant engagement with the walls of said conical bore.

2. A chuck device of the character described, comprising tubular chuck body having an eX- ternally threaded lower end portion, said lower end portion having a conical bore opening outwardly through said end, a plurality of tool grip- .ng jaws mounted in said conical bore, said jaws having bevelled surfaces operating upon the walls o said conical bore in controlling` movement of the jaws toward and from each other, inner edge portions of the jaws having elongated ripper surfaces, said gripper surfaces having rece.N s, means controlling positioning of the jaws one i .th respect to the other, a yoke-shaped spring engaging each of said jaws, each spring having a crosshead and side members, the crossheads being arranged in said recesses, said springs being tensioned to maintain the jaws in constant engagement with the walls of said conical bore, and side members of each of said springs being' bowed and bear upon opposed side surfaces of the jaws in support of the jaws in said conical bore.

3. A chuck device of the character described, comprising a tubular chuck body having an externally threaded lower end portion, said lower end portion having a conical bore opening outwardly through said end. a plurality of tool gripping jaws mounted in said conical bore, said jaws having bevelled surfaces operating upon the walls of said conical bore in controlling movement of the jaws toward and from each other, inner edge portions of the jaws having elongated gripper surfaces, said gripper surfaces having recesses, means controlling positioning of the jaws one with respect to the other, a yoke-shaped spring engaging each of said jaws, each spring having a crosshead and side members, the crossheads being arranged in said recesses, said springs being tensioned to maintain the jaws in constant engagement with the walls of said conical bore, side members of each of said springs being bowed and bear upon opposed side surfaces of the jaws in support of the jaws in said conical bore, and the ends of said side portions of the springs being supported in a part movable with respect to said chuck body.

4. A chuck device of the character described, comprising a tubular chuck body having an externally threaded lower end portion, said lower end portion having a conical bore opening outwardly through said end, a plurality of tool gripping jaws mounted in said conical bore, said jaws having bevelled surfaces operating upon the walls of said conical bore in controlling movement of the jaws toward and from each other, inner edge portions of the jaws having elongated gripper surfaces, a cap-shaped nut mounted on the threaded portion of said chuck body, said nut controlling positioning of the jaws one with respect to the other, a yoke-shaped spring engaging each of said jaws, said springs being tensioned to maintain the jaws in constant engagement with the walls of said conical bore, said jaws being substantially triangular in form, the springs having crossheads, adjacent edges of the jaws being recessed to receive the crosshead of said springs, each of said springs having bowed side portions bearing upon opposed side surfaces of the jaws in support of the jaws in said conical bore, a ring disposed between the nut and said jaws, and said springs being coupled with said ring.

5. In chuck devices employing a plurality of circumferentially spaced tool gripping jaws and a manually operated member for controlling positioning of adjacent gripper edges of the jaws with respect to each other, the chuck body, in which the jaws are mounted, having a conical bore, said jaws having bevelled surfaces engaging the walls of the conical bore, yoke-shaped springs coupled with said jaws and having side members engaging opposed surfaces` of the jaws to support the jaws in predetermined alinement in said conical bore, means engaging the springs for circumferentially spacing the jaws one with respect to the other, adjacent gripper edges of the jaws having recesses, and said springs having crossheads arranged in said recesses of the jaws.

6. In chuck devices employing a plurality of circumferentially spaced tool gripping jaws and a manually operated member for controlling positioning of adjacent gripper edges of the jaws with respect to each other, the chuck body, in which the jaws are mounted, having a conical bore, said jaws having bevelled surfaces engagaeeavn ing the walls of the conical bore, yoke-shaped springs coupled with said jaws and having side members engaging opposed surfaces of the jaws to support the jaws in predetermined alinement in said conical bore, means engaging the springs for circumferentially spacing the jaws one with respect to the other, adjacent gripper edges of the jaws having recesses, said springs having crossheads arranged in said recesses of the jaws, and the side members of the springs engaging side surfaces of the jaws being bowed.

7. In Ichuck devices, a chuck body having a conical bore at one end, a plurality of gripping jaws spaced circumferentially insaid body, means rotatable on the `chuck body for moving gripper edges of said jaws toward and from each other in engaging and disengaging a' tool for support in the chuck body, each jaw having a yoke-shaped spring for maintaining the jaws in constant engagement with said bevelled bore, said jaws having recesses on inner gripper edges thereof, said springs having crossheads operating in said recesses and side members engaging side surfaces of said jaws, said jaws being rotatable in the bore in movement of the jaws toward and from each other, and said springs maintaining the jaws in circumferential spaced relationship to each other.

8. In chuck devices, a chuck body having a conical bore at one end, a plurality of gripping jaws spaced circumferentially in said body, means rotatable on the chuck body for moving gripper edges of said jaws toward and from each other in engaging and disengaging a tool for support in the chuck body, each jaw having a yoke-shaped spring for maintaining the jaws in constant engagement with said bevelled bore, said` jaws having recesses on inner gripper edges thereof, said springs having crossheads operating in said recesses and side members engaging side surfaces of said jaws, said jaws being rotatable in the bore in movement of the jaws toward and from each other, and means with which said springs are coupled for maintaining the jaws in circumierentially spaced relationship to each other.

MELVIN H. EMRICK.

References Cited in the i'lle of this patent UNITED STATES PATENTS Number Name Date 1,593,908 Miller July 27, 1926 1,620,440 Cary Mar. 8, 1927 1,775,992 Emrick Sept. 16, 1930 1,985,586 Stoner Dec. 25, 1934 2,253,345 Palmgren Aug. 19, 1941 

